Liquid fuel burner



1934- .P. R. JOHNSON LIQUID FUEL BURNER 2 Sheets-Sheet 2 Filed Aug. 18. 1932 atented Oct. 30, 1934 UNIT!) STATES PATENT OFFICE LIQUID FUEL BURNER Ferry R. Johnsn, Chieagn, 111. Application August 18, 1932, Serial No. 629,337

6 Claims.

This invention relates to improvements in a liquid fuel burner of the type primarfly used for heating stoves and ranges.

My improvements are directed to the design 6 of a liquid fuel burner in which the fuel is vaporized and burned in an annular ohamber to which air is admitted thmugh perforated walls surrounding the combustion space.

It is an object of my invention to disclose a .10 design of fuel burner which is highly eificient and conomical in the cor1sUmption of fuel and in which the combustion of the fuel vapor will take place substantiafly throughout the height of the burner, -wheieby an intense heat is developed.

A particular objectaof my invention relates to the design of the cylindrical screens which form the dividing walls between the combustion space and the air. 1 have found that by punching out small strips of material substantiafly over the entire area of the dividing wall in such a manner that the strips are integral at their ends with the wall and separate from the body metal on the upper and lower sides thereof, that there Will be formed a dividing wall having a plurality of openingS through which air may flow and be baflied and spread to flow boch upwards and downwards into the combustion spaoe. An important function of my improved dividing wall is to prevent direct lateral admission of the air into the combustion space and to avoid entrance of the air all in the same direction, such as upward, but instead the air is caused t0 fiow into the combustionspace bothupwards and downwards at a plurality cf points.

Further improvements of my invention are directed to the novel design of means within the center portion of the burner intended to drawtheheat down from the top portion of the burn er'and to spread the heat throughout the lower portion of the burner in such a manner as to preheat the fuel and air.

- Various 0ther features of novelty and advantages of my improvemencs will be more readily apparent from the following description taken in connection with the attached drawngs.

Figure'l is an elevation of a burner unit;

. Figure 2 is a sectional elevation taken on the plane indicated 22 in Figure 3; Figure 3 isa plan view of the burner unit;

Figure 4 is a plan view of the base; Figure 5 is a partial horizontal sectiontakeh throughthe reticulated screens and shown at an enlarged scale;

Figure 6 is a partial horizontal section similar 5.6- ,to Figurebut ill1strating a modification.

The burner is designed for installation in a stove, range or other heating device to be used for cooking or heating purposes. The liquid fuel may be fd from a suitaole reservoir in such a manner as to maintain a constant lever fuel Within the burner. The liquid fuel is conducted 130 the burner through the pipe 10 which is connected to the base member 12.

As shown in the plan view of the base 12 in Figure 4, the fuel is directed upwardly tln0ugh the pipe 10 through 3. passage 14 into an annular trough 16. The base has a central circular opening 18 su1rounded by a cylindrical wall 20. The wall 20, as shown in Figure 2, extends for some distance above the bottom of the trough 16. The trough 16 is substantially surrounded by a raised rib 22 which is spaced outwardly With respect to the cylindrical wall 20. However, the rib has a cutaway portion 24 which permits fiow of the fuel into a second trough 26, the bottom of which is somewhat below the bottom of the first trough 16. The trough 26 is surrounded on its outer side by the raised cylindrical rib 28 which extends substantafly to the same level as the inner cylindrical wall 20. Finally the base member 12 has 30 integrally formed therewth an outer ringshaped member 30 which is supported from the inner ringshaped portion by spaced bosses 32, thereby leaving openings 34 which, as Will be later apparent, permit the upward fiow of air. 8

The outer ring 30 forms an annular fuel feeding groove 36 surrounded by an inner 1aised rib 38 and an outer raised rib 40. The bosses 32 include passageways 42 which as illustrated in Figure 2, permit fioW of the fuel from the trough 26 into the outer annular groove 36. The groove 36 is adapted to receive an annular wick 44, the top of which may be trimmed to extend slightly above the ribs 38 and 40. The ribs 38 and 40 are rabbeted in order to serve as supports for cylindrcal reticlated screen members.

Thus, there is provided an outer screen member 46 supported and positiohed by the cylindrical rib 40. A smaller screen 48 is mounted inside ofthe rib 38, A stil1 smaller cylindrical screen 50 is positioned by the cylindrical rib 28. The innermost screen 52 is supported on a rem0vab1e blook 54 which has a cylindrical portion 56 fitting within the central opening 18 of the base member 12. The member 54 has an enlarged ringshaped portion 58 which seats upon the circular rib 20 and substantiafly covers the innermost oil feeding trough 16. The ring-shaped portion 58 is upwardly fianged in order to position the clin= It will be apparent that the four cyiindrical screens are concentricafly mounted. The screens 46 and 48 define an annular combustion space 60.

The screens 56 and 52 define an annular combustion space 62. The annular space 64 between the screens 48 and 50 receives air from the openings 34 in the base member in order to feed the air into the combustion spaces.

The top of the burner illustrated in Figures 1 and 2 includes a removable cap member 66. The central portion 01 the cap member 66 is or substantiaily the same diameter as the inner screen 52 in order to close the open upper end thereof.

The cap member 66 also includes a ring-shaped portion 68 adapted to cover the annular space 64 between the screens 48 and 50. The ring-shaped portion 68 is supported from the inner portion or the cover member by spaced radial arms 70.

The arms 70 have integral 1ug portions 72 depending into the combustion space 62 and serving to hold the screens and 52 in p1oper position. The arms also include depending lugs 74 fit- 25.; ting into the combustion space 60 and serving to position the scieens 46 and 48.

The particular formation of the reticuiated cylindrical screens is a novel feature of the present improvements. The new design is most clear- 3oa ly illustrated in the enlargd view of Figure 5. It

will be noted that annular strips of the continuons cylindricai wall are pressed into the shape shown by sectional view of Figure 5. Thus, the outer screen 48 includes strips 76 which present 353 a wavy or corrugated appearance, portions or the strips being pressed inwards to such an extent as to leave vertical openings 78, as viewed from the upper end of the cylindrical screen. It will therefore be understood that air may pass into 4f2jthe combustion space either upwards or downwards through the vertical opening 78 but the air is prevented from passing directly inwards due to the shielding efiect of the continuous material in the screen 46. On the other hand the flames cannot pass directly outwards as would be possible if the material was punched out to ieave free openings. It will be noted that the corrugations are pressed inward from the exterior of the cylindricai member 46 while in the cylindrical member 48 the corrugations are pressed outward- 1y. Thus the burning of the combustible vapor in the annular space 60 produces a suction action tending to draw in air from both sides of the combustion space. This action coeurs throughout 55 the entire height of the cylindrical screens A modified design is shown in Figure 6 in which the corrugations 86 and 82 are pressed outward- 1y with respect to the combustion space. It is believed that the form shown in Figure 5 is more C33; desirable since the inward pressed corrugations tend to promote agitation and mixing of the combustible vapor.

It is highly desirablein order to obtain comp1ete combustion of the fuel vapor to insure burn- 5: ing of the vapor entirely throughout the height of the burner and I have shown in Figure 2 an element Which is of assistance in conducting the heat downwardly from the top portion of the burner which is normally the hottest portion of .733; the burner and to throw out the heat adjacent the bottom of the burner. This element also serves to some extent in preheating the incoming air and fuel. I show a cone-shaped member 84 Which is seated upon the part 54. This (6 ;cone-shaped member is composed of a lava product which is refractory and which becomes incandescent when highly heated. Thus as the top of the cone becomes heated, the heat is conducted downwardly and spread outwardly until the entire cone is incandescent, whereupon the heat at the bottom of the cone is taken up by the fuel vapor rising through the annular combustion space 62.

According to my invention, a more efiicient combustion of the fuel is obtained throughout the entire vertical height of the burner. It is found particuiarly important to trap the fiame combustion within the combustion space and, by the manner in which I have formed the baffied air admission apertures in the she1ls, the flame does not travel rapidly upwards to concentrate the heat at the top of the burner but instead the air is drawn inwards to pass both upwardly and downwardly within the combustion space and to prevent 1apid movement of the fiame. Furthermore, by the use of the refractory elements, Which become incandescent when highly heated, the heat is retained in the burner and the bottom of the portion of the burner is maintained substantially as hot as the top por-- tion. It has been found that a much higher temperature can be obtained when the refractory elements are employed than without such elements.

I claim:

1. In an oil burner, spaced, concentric walls forming an annular combustion chamber therebetween, one of said walls including a plurality of openings therethrough, said openings being formed by strips of the wall material pressed from the body of said wall inwardly into said chamber in such a manner as to form vertically open passages beneath and above each strip adjacent to the surface of said wall.

2. In an oil burner, a pair of cy1indrical metallic members concentricafly positioned and spaced to form an annu1ar combustion chamber therebetween, said metallic members having apertures to admit air to said combustion chamber, the apertures in said metallic members being shielded by strips of metal pressed inwardiy into said chamber from the body of said metallic members in such a manner as to form vertically open passages beneath and above the strips and in communication with the apertures of said members.

3. In an oil burner a pair of cylindrical me-' tallic members forming inner and outer walls of an annular combustion space, each of said metallic members having a plurality of air admission apertures formed by inwardiy pressed strips of metal, each of said strips being out away from the body of the metallic members in such a manner as to form vertically open passages within the combustion space beneath and above each strip of material for conducting the admitted air upwardiy and downwardiy into said combustion space for mixing with the combustible vapor.

4. In an oil burner having an annular combustion space formed by an apertured wall. said wall having strips of the wall material pressed from the body of the wall to form the apertures thereof, said strips serving as bafiies for directing the air drawn into the combustion space upward- 137 and downwardly therein.

5. In an oil burner, a pair of cy1indrical shells forming an annular combustion space therebetween, each of said shel1s having a plurality of air admission apertures and bafiies within the space through said apertures to cause said air to flow both upwardly and downwardly from each aperture into said combustion space and a heatabsorbing refractory member Within the inner of said she1ls, said member having an increasing cross sectional area from the top towards the bottom thereof, said member being adapted to become incandescent throughout when the burner is in operation.

FERRY R. JOHNSON. 

